JPH0424385B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyamide resin mixed composition that has characteristics such as rigidity, strong resin properties, and heat resistance, and has improved discharge stability during kneading using an extruder. Polyamide has excellent mechanical properties, electrical properties, chemical resistance, processability, etc., and is therefore widely used in many fields such as textile films and plastic products. As the demand for polyamide increases, the required performance becomes diversified, and there are cases where a single material cannot satisfy the requirements. Therefore, attempts are being made to combine two or more materials to create a material that complements the shortcomings of each material. Traditionally, roasting has been commonly practiced. For example, polycaproamide (nylon 6)
or polyhexamethylene adipamide (nylon 66)
Although it has high strength, rigidity, and excellent heat resistance, it has high water absorption, dimensional changes and physical property deterioration due to water absorption are large, and it has insufficient resistance to metal halides such as calcium chloride and zinc chloride.
There are drawbacks such as cracks occurring when these metal salts come into contact with each other. On the other hand, so-called high-grade polyamides such as polyhexamethylene sebacamide (nylon 6/10), polyhexamethylene dodecamide (nylon 6/12), polyundecaneamide (nylon 11), and polydodecanamide (nylon 12) are flexible. , bending fatigue resistance, low temperature impact resistance, dimensional stability,
Although it has good resistance to metal halides, it has unsatisfactory rigidity and heat resistance, and is expensive, so it is not in great demand. Under the above circumstances, a mixture of nylon 6 or nylon 66 and a series of high-grade polyamides provides a material with extremely well-balanced physical properties that combines the characteristics of each polyamide, and is used for various automobile parts, mechanical parts, electrical parts, etc. However, when melt-kneading these two polyamides using an extruder, serious problems were encountered. The problem is that the discharged material from the extruder exhibits a melt fracture state, making it extremely difficult to stably and continuously take off the kneading gut. Therefore, the present inventors aimed to improve the stability of discharge from an extruder without impairing the above-mentioned excellent characteristics of a mixture of nylon 6 or 66 and high-grade polyamide such as nylon 6/10. As a result of extensive studies, it was discovered that a remarkable effect can be achieved by incorporating a small proportion of a modified polyolefin having various functional groups or a polyamide containing an aromatic component, and the present invention has been achieved. That is, the present invention provides (A) 20 to 95% by weight of a polyamide whose main constituent units are caproamide units and/or hexamethylene adipamide units;
(B) Aliphatic amino acids with 11 or 12 carbon atoms, lactams and aliphatic diamines with 6 to 12 carbon atoms and 6 carbon atoms
-100 parts by weight of a mixture of 5 to 80% by weight of polyamide obtained by melt polymerizing at least one selected from equimolar salts with 12 aliphatic dicarboxylic acids (excluding hexamethylene diammonium adipate), the following: Polymers of group () or below ()
The object of the present invention is to provide a polyamide resin composition containing 1 to 40 parts by weight of the polymers of groups (1) and (2). Group (): modified polyolefins having at least one functional group selected from carboxylic acids, carboxylic acid metal salts, carboxylic esters, acid anhydrides, and epoxy groups. Group (): polyamides whose main constituents are aromatic amino acids, aromatic diamines and/or aromatic dicarboxylic acids. The polyamides used as component (A) in the present invention include polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 66), and copolyamides and mixed polyamides containing these as main components. The degree of polymerization of the polyamide used here is not particularly limited, and polyamides having a relative viscosity generally within the range of 2.0 to 5.0 can be arbitrarily selected. Representative examples of the polyamide as component (B) used in the present invention include 11-aminoundecanoic acid,
Equimolar salts of 12-aminododecanoic acid, ω-laurolactam, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, etc. and adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, etc. (However, hexamethylene diamine and adipic acid) Polyamide obtained by melt polymerizing at least one selected from the following (excluding equimolar salts with acids),
For example, nylon 6,9, nylon 6,10, nylon 6,12, nylon 11,6, nylon 12,6,
These include nylon 11, nylon 12, or copolymers containing these as main components. The degree of polymerization of the so-called higher polyamide used here is not particularly limited;
Any polyamide whose relative viscosity is usually within the range of 1.7 to 4.5 can be selected. In the present invention, the polymer used as an ejection stability improver when mixing component (A) polyamide and (B) component polyamide is selected from the following groups () and (). That is, group () refers to modified polyolefins having at least one functional group selected from carboxylic acids, carboxylic acid metal salts, carboxylic esters, acid anhydrides, and epoxy groups, such as ethylene/acrylic acid copolymers, ethylene/meth Acrylic acid copolymer, ethylene/fumaric acid copolymer, ethylene/methacrylic acid/zinc methacrylate copolymer, ethylene/acrylic acid/sodium methacrylate copolymer, ethylene/isobutyl acrylate/methacrylic acid /zinc methacrylate copolymer, ethylene/methyl methacrylate/methacrylic acid/magnesium methacrylate copolymer, ethylene/ethyl acrylate copolymer, ethylene/vinyl acetate copolymer, ethylene/vinyl acetate g-acrylic acid copolymer (“g” represents graft), ethylene-g-maleic anhydride copolymer, ethylene/propylene-g-maleic anhydride copolymer, ethylene/propylene-g-acrylic acid copolymer Polymer, ethylene/1-butene-g-fumaric acid copolymer, ethylene/1-hexene-g-itaconic acid copolymer, ethylene/propylene-g-
Endobicyclo[2,2,1]-5-heptene-
2,3-dicarboxylic anhydride copolymer, ethylene/
Propylene-g-glycidyl methacrylate copolymer, ethylene/propylene/1,4-hexadiene-g-maleic anhydride copolymer, ethylene/
Propylene/dicyclopentadiene-g-fumaric acid copolymer, ethylene/propylene/norbonadiene-g-maleic acid copolymer, ethylene/glycidyl methacrylate copolymer, ethylene/vinyl acetate/glycidyl methacrylate copolymer It is also possible to use two or more of the above polyolefin resins in combination. These modified polyolefins can be produced by conventionally known methods, such as those disclosed in Japanese Patent Publication No. 39-6810, Japanese Patent Publication No. 46-27527,
Special Publication No. 49-31556, Publication No. 50-2630,
Special Publication No. 52-43677, Publication No. 53-5716,
It can be produced according to the methods disclosed in Japanese Patent Publication No. 53-19037, Japanese Patent Publication No. 53-41173, Japanese Patent Publication No. 56-9925, etc. As the modified polyolefin used in the present invention, it is particularly preferable to use ethylene-based ionomer resins that are generally commercially available under the trade names "Surlyn,""Hylamin," and "Copolene." Group () also includes polyamides whose main constituents are aromatic amino acids, aromatic diamines and/or aromatic dicarboxylic acids, such as para-aminomethylbenzoic acid, para-aminoethylbenzoic acid, meta-aminomethylbenzoic acid, paraxylylene diamine, The main components are metaxylylene diamine, terephthalic acid, isophthalic acid, etc., and other components or copolymerization components used as necessary are ε-caprolactam, ω-laurolactam,
Lactams or amino acids such as 11-amine undecanoic acid, 12-aminododecanoic acid, hexamethylene diamine, undecamethylene diamine, dodecamethylene diamine, 2,2,4-/2,4,4-trimethylhexamethylene diamine, para-aminocyclohexyl Methane, para-aminocyclohexylpropane, bis(3-methyl,4-aminocyclohexyl)methane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, isophoronediamine, etc. with adipic acid, azelaic acid , sebacic acid, dodecanedioic acid, and other equimolar salts, which can be melt-polymerized. A typical example of a polyamide made of these components is a copolymer polyamide (nylon) of para-aminomethylbenzoic acid and ε-caprolactam.
AMBA/6), polyamide (nylon
MXD6), hexamethylenediamine isophthalate or hexamethylenediamine terephthalate as the main component, ε-caprolactam, 12-
Polyamide (nylon 6I, 6I/6T, 6I/12, 6T/6, 6T/
66,6I/PACM-6),2,2,4-/2,4,
Polyamide (nylon) whose main component is 4-trimethylhexamethylene diamine terephthalate
TMDT, TMDT/6I), main component is para-aminocyclohexylmethane isophthalate or bis(3-methyl,4-aminocyclohexyl)methane isophthalate, hexamethylenediamine dodecanedioate, ε-caprolactam, 12 −
Polyamide containing aminododecanoic acid as a copolymer component (nylon PACMI/612, PACM I/6,
DMPACM I/12), etc., and it is also possible to use two or more of the above polyamides in combination.
These polyamides can usually be obtained by a combination of pressurization, normal pressure, and reduced pressure operations at a temperature of 250 to 350°C, and there are no particular restrictions on the degree of polymerization of the obtained polyamide, and it is necessary to Any polyamide within the range can be selected. The resin composition of the present invention comprises (A) 20 to 95% by weight, more preferably 25 to 95% by weight of a polyamide whose main constituent units are caproamide units and/or hexamethyleneadipamide units, and (B) 5 to 95% by weight of a higher polyamide. 1 to 40 parts by weight, more preferably 2 to 35 parts by weight of () modified polyolefin and/or () aromatic polyamide are blended to 100 parts by weight of a mixture of 80% by weight, more preferably 5 to 75% by weight. Consisted of. When the blending amount of component (A) polyamide is less than 20% by weight or the blending amount of component (B) polyamide is less than 5% by weight, the discharge of the mixture from the extruder is not so unstable, and the discharge stability is particularly improved. Since there is no need to take measures such as adding agents,
It is not a subject of the present invention. If the blending amount of () modified polyolefin and/or () aromatic polyamide is less than 1 part by weight with respect to 100 parts by weight of the mixture of (A) component polyamide and (B) component polyamide, the effect of improving the extrusion stability from the extruder is insufficient. This is not preferable because it is difficult to take off the kneading gut continuously. On the other hand, if the blending amount of () the modified polyolefin and/or the aromatic polyamide exceeds 40 parts by weight, the decrease in rigidity, heat resistance, etc. becomes noticeable, and the inherent strong characteristics of the polyamide are impaired, which is not preferable. (A) component polyamide, (B) component polyamide and ()
The method of mixing the modified polyolefin and/or () aromatic polyamide is not particularly limited, and a commonly known method can be employed. In other words, pellets, powders, pieces, etc. of each component are uniformly mixed using a high-speed stirrer, and then melted and kneaded all at once using a single-screw or multi-screw extruder with sufficient kneading capacity. A method in which a polyamide mixture of components (A) and (B) is charged, and () modified polyolefin and/or () aromatic polyamide is added and melt-kneaded from another supply port of the same extruder, component (A). Methods of blending pellets obtained by first kneading polyamide with () modified polyolefin and/or () aromatic polyamide and component (B) polyamide using an extruder, various modifications of these methods, etc. Can be adopted. The resin composition of the present invention is generally molded by known molding methods for thermoplastic resins such as injection molding, extrusion molding, blow molding, and vacuum molding, but in particular various automobile parts obtained by injection molding or extrusion molding, Mechanical parts, electrical parts, such as cooling fans, radiator tanks, cylinder head covers, oil pans, brake piping, fuel piping,
Exhaust gas system parts, connectors, gears, gears, valves, tubes, pipes, packings, monofilaments, wire sheaths, switches, sheets, etc. are useful. The composition of the present invention may also contain other ingredients, such as pigments, as long as they do not impair its moldability or physical properties.
Dyes, reinforcing agents, fillers, heat resistant agents, antioxidants, weathering agents, lubricants, crystal nucleating agents, antistatic agents, plasticizers, flame retardants, antiblocking agents, other polymers, etc. can be added and introduced. . In particular, compositions further containing reinforcing materials and fillers such as glass fiber, carbon fiber, asbestos fiber, talc, calcium carbonate, wollastenite, and potassium titanate whiskers,
We can provide materials with high practical value that have excellent rigidity and heat resistance. The present invention will be explained in further detail by giving examples below. The physical properties of the test pieces described in Examples and Comparative Examples were measured in accordance with the following method. (1) Relative viscosity: JIS K6810 (2) Tensile test: ASTM D638 (3) Bending test: ASTM D790 (4) Izot impact test: ASTM D256 (5) Heat distortion temperature: ASTM D648 (6) Water absorption: ASTM D570 (7) Metal halide resistance test: After treating the tensile test piece in boiling water for 24 hours, the maximum curvature part
The specimen was bent so that an initial load stress of Kg/cm ² was applied, and in that state it was immersed in a 50% zinc chloride aqueous solution at 23°C to measure the time until cracking occurred in the specimen. (8) Bending fatigue test: A test piece with a width of 5 mm and a length of 80 mm was cut from a heat-pressed sheet with a thickness of 1 mm, and was subjected to a load of 1 kg, a bending angle of 270, and a bending cycle using an MIT soft fatigue tester manufactured by Toyo Seiki Seisakusho. 180 times/
The number of times the test piece was bent until it broke was determined under the conditions of 30 minutes. Example 1 Nylon 6:60% by weight with a relative viscosity of 2.80 obtained by melt polymerizing ε-caprolactam and nylon 6.10:40% by weight with a relative viscosity of 2.60 obtained by melt polymerizing hexamethylenediamine/sebacine hydrochloride. blend
Add 5 parts by weight of "HIMILAN" 1706 (Mitsui Polychemical Co., Ltd. ionomer resin, ethylene/methacrylic acid/zinc methacrylate copolymer) to 100 parts by weight, mix uniformly with a high-speed stirrer, and make a 65mmφ
When the mixture was melt-kneaded at 250° C. using a large diameter extruder, the extrusion stability from the extruder was extremely good and pellets of the blend could be easily obtained. After vacuum drying the pellets obtained here, the cylinder temperature is 250℃ and the mold temperature is controlled by an injection molding machine.
Test pieces for measuring various physical properties were molded at 80°C.
The physical properties measured using this test piece when completely dry are as follows, and it was found to be a material with extremely well-balanced physical properties, having characteristics such as rigidity, toughness, and heat resistance. Tensile yield stress: /50Kg/cm ² Tensile elongation at break: >200% Bending yield stress: 960Kg/cm ² Flexural modulus: 25000Kg/cm ² Izotsu impact strength: 6.5Kg・cm/cm Notch Heat distortion temperature (4.64Kg/cm cm ² ): 175°C Water absorption: 1.3% by weight Resistance to metal halides: >100 hours Bending fatigue resistance: 510 times Comparative example 1 Nylon 6 and nylon 6/10 used in Example 1
When the mixture was mixed and kneaded with the same composition and under the same conditions as in Example 1, the discharged material from the extruder exhibited a melt fracture state, and it was extremely difficult to stably and continuously take off the kneading gut. Comparative Example 2 After adding 50 parts by weight of "Himilan" 1706 to 100 parts by weight of the mixture of 60% by weight of nylon and 40% by weight of nylon 6.10 used in Example 1, the same procedure as in Example 1 was carried out. Kneading and injection molding were performed to obtain test pieces for measuring physical properties. The discharge conditions during extruder kneading were extremely smooth and there were no problems at all, but the results of measuring the physical properties of the obtained test pieces when bone dry were as follows:
Rigidity and heat resistance were unsatisfactory. Tensile yield stress: 480Kg/cm ² Bending yield stress: 620Kg/cm ² Flexural modulus: 16000Kg/cm ² Heat distortion temperature (4.64Kg/cm ² ): 147°C Examples 3 to 8 (A) component polyamide, (B ) component polyamide, ()
The type and blending amount of the modified polyolefin and aromatic polyamide () were changed, and the extruder kneading and molding were carried out in the same manner as in Examples 1 and 2, and the discharge state from the extruder and the physical properties of the molded pieces were examined.
The results shown in Table 1 were obtained. In all cases listed in Table 1, the formulation was discharged from the extruder in an extremely good condition, and moreover,
A material with extremely well-balanced physical properties that has characteristics such as rigidity, toughness, and heat resistance can be obtained.

[Table] It was found that glycidyl acid was produced. Example 9 Mixture 100 of 50% by weight of nylon 66 with a relative viscosity of 2.50 and 50% by weight of nylon 6.10 with a relative viscosity of 2.45
“Himilan” 1706: 3 parts by weight,
Nylon 6I with a relative viscosity of 2.05: 4 parts by weight and chopped strand glass fiber TP from Nippon Glass Fiber Co., Ltd.
-24: After adding 45 parts by weight, kneading and injection molding were performed under the same conditions as in Example 2, and the physical properties were measured. The discharge from the extruder during kneading was extremely smooth, and the physical properties when absolutely dry measured using the obtained test pieces were extremely excellent as shown below. Tensile strength: 1400Kg/cm ² Bending strength: 2400Kg/cm ² Flexural modulus: 83000Kg/cm ² Izotsu impact strength: 12Kg・cm/cm notch Heat distortion temperature (18.6Kg/cm ² ): 210℃ Water absorption: 0.8 Weight % Resistance to metal halides: >100 hours

Claims (1)

[Scope of Claims] 1 (A) 20 to 95% by weight of polyamide whose main constituent units are caproamide units and/or hexamethylene adipamide units, and (B) carbon number 11 or 12
aliphatic amino acids, lactams and carbon atoms 6-12
A polyamide 5 to 80 obtained by melt polymerizing at least one selected from equimolar salts of aliphatic diamines and aliphatic dicarboxylic acids having 6 to 12 carbon atoms (excluding hexamethylene diammonium adipate).
A polyamide resin composition comprising 1 to 40 parts by weight of a polymer of the following () group or a polymer of the following () group and () group with respect to 100 parts by weight of a mixture of % by weight. Group (): modified polyolefin having at least one functional group selected from carboxylic acid, carboxylic acid metal salt, carboxylic ester, acid anhydride, and epoxy group (group): aromatic amino acid, aromatic diamine and/or Polyamide whose main component is aromatic dicarboxylic acid.